"heim" pronounce HYME means "home" in German. "linde" is the German word for a tree (I think it's called Linden Tree or something in English).
"peaceful" means "friedlich" in German. So I have no idea where they got this from. Emmeline definitely does NOT mean "peaceful home" in German. "heim" doesn't even appear in the name Emmeline (except for when you pronounce it to rhyme with "wine" then it rhymes as in "line", "hyme").
The source would be one of those baby name sites who try to make a name more attractive by changing the meaning a bit. I wouldn't trust these sites.
Emmeline would be a form of Emma or Amelia (doesn't matter as they come from the same source anyway). I think the Emma theory is very likely to be true.
I think the chances that it means "peaceful home" are very slim.